Maxim MAXQ MCU

Paul Curtis wrote:

> "Jim Granville" <no.spam@designtools.co.nz> wrote in message
> news:JQcZb.25252$ws.3092325@news02.tsnz.net...
> 
>>  Acillies Heel: Not enough info, but the fixed stack looks a problem
> area.
> 
> The hardware stack is a synthesis "variable" constant.

Which means what, in terms of real silicon ?
  To someone in the field who has just blown the stack limit,
being told the 'hardware stack is a synthesis "variable"
constant' might not give much comfort.... :)

> 
>>  They have one of the strangest OPCODE descriptions I have ever seen,
>>so it is not possible to detemine the reach-corners ( and thus at
>>what data-sizes your code suddenly gets bigger )
> 
> 
> The instruction set is simple.  It's not the instruction set you need to
> worry about, it's the other bits. 

  The instruction set gives important clues on the code-knee regions -
ie those thresholds, where you run out of reach of one level of opcodes,
and need more.
  To look the best in benchmarks, you choose code to run just under 
those knees, but the real world is not as flexible..


 > The encoding of instructions is simple
> and ortogonal, but the Maxim journal doesn't go into much detail, so you
> need to wait for that.  However, C compilers should fit well on the micro,
> if they're sufficiently tuned to the architecture.
> 
> 
>>  Telling Omission ?: No benchmarks with 80C51, and eZ8 devices. Both
>>these have direct memory access opcodes, and the Z8 also includes a
>>register frame pointer. For the small data sets of embedded
>>microcontrollers, this makes for smaller code size.
> 
> 
> The controller is quite capable of running code at lightning speed.  Its
> features are a real hoot!

  You seem to know more than what MAXIM have published, I'll track this 
with interest.
  I still call it a brave move, esp. from someone like Maxim with
no previous own-processor track record, and unused to that market space.

-jg

Jim Granville <no.spam@designtools.co.nz> writes:

>   Seems they now have post-layout numbers (but still tagged
> simulations), and as often happens, the reality is not quite what they
> hoped, and the claimed power margins have taken a hit...
>   Next will be numbers from real silicon :)

And there are some very interesting numbers which will not
be available in a while. E.g., MIPS/$... The threshold of
adopting a new processor is rather high. For a new architecture
to be competitive, it has to have some real strenghts. Just
being "nice" is not enough.

When talking about speed, there are devices like Philips LPC21xx
series. They are not 8-bit chips but they are rather reasonably
priced and very fast with rather skinny power budget. Or low-end
eight-bit processors (small PICs, many 51s, ATtinys) with price
tags below one dollar. At the moment the Maxim/Dallas processor
do not seem to compete in the mainstream. They are more aimed at
people who want faster '51. MAXQ must target an entirely different
market, as there is no existing user population.

It'll be interesting to see the first real commercially available
products "later this year".

- Ville

-- 
Ville Voipio, Dr.Tech., M.Sc. (EE)

Ville Voipio wrote:
> Jim Granville <no.spam@designtools.co.nz> writes:
> 
> 
>>  Seems they now have post-layout numbers (but still tagged
>>simulations), and as often happens, the reality is not quite what they
>>hoped, and the claimed power margins have taken a hit...
>>  Next will be numbers from real silicon :)
> 
> 
> And there are some very interesting numbers which will not
> be available in a while. E.g., MIPS/$... The threshold of
> adopting a new processor is rather high. For a new architecture
> to be competitive, it has to have some real strenghts. Just
> being "nice" is not enough.

Very true.
Since they are 'beating the MIPS/mA drum', I thought I'd
reality check into what real & shipping 'better process 80C51 variants'
come in at :

MAXQ (Simulated) = 3.3MIPS/mA  -> 330 MIPS/W

Cygnal devices (Avail for some time) = 600-1100 MIPS/W

Philips P87CL888 (also avail or some time) = 700 MIPS/Watt @ 3V, 
climbing to 1800 MIPS/Watt at 2V

Guess that explains why these devices are missing from the MAXQ 
comparison line-ups :)


  The P87CL888 is interesting in that it is an ASYNC 80C51 - ie each 
opcode executes as fast as the silicon allows, then it goes onto the 
next. Result is automatic thermal/Vcc tracking, and max possible time
spent in IDLE.

> 
> When talking about speed, there are devices like Philips LPC21xx
> series. They are not 8-bit chips but they are rather reasonably
> priced and very fast with rather skinny power budget. <snip>

.. and also now the new ADuC7xxx devices from ADi ....

-jg